Johnson County, IA Noise Ordinances: Decibel Limits (2026)
Key Facts
- BESS noise cap
- 60 dBA, 1-hour average
- Wind facility noise cap
- 45 dBA at occupied building
- Measurement point
- Non-participating residence or property line
- General noise ordinance
- Not in this UDO volume
- Enforcement
- Zoning Administrator, Chapter 8:8
Summary
Johnson County's zoning code sets numeric decibel caps only for specific conditional uses, not general residential noise. Battery energy storage systems are capped at 60 dBA and commercial wind turbines at 45 dBA, both measured at the nearest non-participating residence or property line.
7. Noise. The 1-hour average noise generated from the battery energy storage systems, components, and associated ancillary equipment shall not exceed a noise level of sixty decibels (60 dBA) as measured at the outside wall of any non-participating residence or occupied community building or the property line. Applicants may submit equipment and component manufacturer noise ratings at the time of application to demonstrate compliance... A. Audible Sound. Wind Energy Facility shall not exceed forty five (45) dBA, as measured at the exterior of any Occupied Building on a Non-participating Landowner's property.
Official source re-checked September 7, 2026: the cited page had not changed since it was quoted.
Full Breakdown
The Unified Development Ordinance (Volume Two) does not include a general residential decibel limit or a day/night noise chart; that kind of nuisance-noise rule sits in Volume One, the county's general code, which is a separate instrument. What the UDO does set are hourly decibel caps tied to specific energy-generation conditional uses in the unincorporated county. 24(F)(7), Tier 2 battery energy storage systems, allowed as a primary use in the RE district and a conditional use in the A and CH districts, may not generate more than a 1-hour average of 60 dBA measured at the outside wall of any non-participating residence, an occupied community building, or the property line.
Applicants can submit manufacturer noise ratings with their application, and the Zoning Administrator may require post-installation sound-pressure-level testing from sampled perimeter locations, including in response to a noise complaint on an already-operating system. 1-1989 measurement procedures. Both standards are compliance conditions attached to the conditional-use or site-plan approval for those facility types, not a blanket zoning-wide noise ordinance; a property owner with a noise complaint about anything other than a permitted battery-storage or wind-energy installation has no numeric decibel standard to point to in this volume.
Violations & Fines
Noncompliance is enforced as a condition of the underlying conditional use or site plan approval: the Zoning Administrator can require sound-pressure testing, and Chapter 8:8 enforcement (investigation, infraction citations, stop-work orders, permit revocation) applies, with county infraction penalties up to $750 for a first offense and $1,000 for a repeat offense of the same standard.
Frequently Asked Questions
Does Johnson County have a residential noise ordinance with decibel limits by time of day?
Where is the 60 dBA battery storage limit measured?
Can the county require noise testing after a wind or battery facility complaint?
Sources & Official References
Other rules in Johnson County
Compare Johnson County to another location·View the Iowa noise ordinances overview
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